media: i2c: imx258: Disable digital cropping on binned modes

The binned modes set DIG_CROP_X_OFFSET and DIG_CROP_IMAGE_WIDTH
to less than the full image, even though the image being captured
is meant to be a scaled version of the full array size.

Reduce X_OFFSET to 0, and increase IMAGE_WIDTH to the full array.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>